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<title>Graphviz todo list 30-January-2009</title>
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<h1>Graphviz todo list 30-January-2009</h1>
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The 4 categories give a rough time as to when a task should be done, 
and reflect an assessment of the task's ease multiplied by its importance. 
Thus, orthogonal layouts are extremely important but not easy,
so they fall into category 2. The following denote owners:<br>
AB=<A HREF=mailto:arif@research.att.com>Arif Bilgin</A><br>
ERG=<A HREF=mailto:erg@graphviz.org>Emden Gansner</A><br>
JCE=<A HREF=mailto:ellson@graphviz.org>John Ellson</A><br>
SCN=<A HREF=mailto:north@graphviz.org>Stephen North</A><br>
YH=<A HREF=mailto:yifanhu@graphviz.org>Yifan Hu</A><br>

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<H2>Category 0</H2>
<pre>
ALL - Revise the buglist
SCN - Update dot/neatoguide
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<H2>Category 1</H2>
<pre>
SCN - Lightweight edge labels in dot
? - Lightweight node labels in dot, just placed outside nodes.
SCN - Treemaps
JCE - Extend attribute set for line styles
JCE - Allow arrowheads in the middle of edges
JCE - Support single, uniform font descriptors &#224; la pango
?   - Move generic node adjustment and spline routing out of neato
ERG - New text labels with font elements &lt;B&gt;, &lt;I&gt;, &lt;TT&gt;, etc. (support via fontconfig or egregious hacks)
AB  - Create Graph editor for Topview/Graphviz with OpenGL and GTK. (smyrna - in process) (Deprecate use of lefty)
YH/ERG - Clusters in sfdp
YH/ERG - Fixed nodes in sfdp
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<H2>Category 2</H2>
<pre>
SCN/AB - New dot core:
   - cgraph
   - new rank assignment (have prototype)
   - new mincross + clusters (partial prototype)
   - symmetrize layouts
  - Ulrik's improvements with network simplex
JCE - Shapes
	- SVG grammar or other grammar to specify node and arrow shapes
	- user-defined nodes in all code generators
YH/ERG - additional graph packing strategies
? - Filters for GraphML and Chaco formats.
? - Library for bundled edges (Given two sets of nodes, with positions, 
forming a bipartite graph, return splines to bundle the edges together)
? - better spacing of edges along the side of a node, especially
exposed port sides. Perhaps extend compass points to S, N, E, W to
mean anywhere along that side.
? - Tabular layout in rows and columns in dot (swim lanes)
? - Enable arbitrary depth clusters in neato using IPSEP
? - Allow mixed edge types within the same graph

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<H2>Category 3</H2>
<pre>
Generic label placement, with and without modifying graph layout.
Support for compound graphs.
Spline router improvement (Gordon's improvements, alpha adjustments, fewer
  inflection points)
Fast incremental hierarchical layout
Edge routing with just two vnodes per edge (after Kaufmann)
Graph language improvements
  local name spaces
  subclassing
Shapes - new parallelogram shape where angle is fixed for varying text
Orthogonal layouts.
Support rank=min/max within the context of a cluster
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<H2>General R&D directions</H2>
<pre>
Incremental layouts
Dot with orthogonal, coalesced edges (e.g., <A  HREF=http://upload.wikimedia.org/wikipedia/en/thumb/7/74/Uml_diagram.svg/700px-Uml_diagram.svg.png>this</A>)
Constraint-based layouts
Display of large-graphs (hair ball problem)
 - relaxing constraining edges 
 - edge bundles
Venn diagrams 
Integration of geographic info - maps
</pre>
<H2>Done</H2>
<pre>
JCE - Extend attribute set for line thickness
ERG - New text labels with font elements &lt;FONT&gt;
ERG - Allow edges as line segments and polylines
ERG - New multiedge code
YH/ERG - New overlap adjustment strategies
YH - Faster fdp (sfdp)
ERG - Variable port depending on layout
ERG - Better aspect ratio in dot
ERG - New orthogonal routing code
JCE - use floats not ints where appropriate
YH - Filters for Matrix Market
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<H2>Retired</H2>
<pre>
JCE - Revise GV_FILE_PATH to work as directory list; remove loose ends
ERG - eliminate the nonlinear adjustment
 - use convex hull or alpha shapes
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